Graphite electrodes are used in the steel industry to melt the metals and other ingredients used to form steel in electrothermal furnaces. The heat needed to melt metals is generated by passing current through one or a plurality of electrodes, usually three, and forming an arc between the electrodes and the metal. Electrical currents in excess of 50,000 amperes are often used. The resulting high temperature melts the metals and other ingredients. Generally, the electrodes used in steel furnaces each consist of electrode columns, that is, a series of individual electrodes joined to form a single column. In this way, as electrodes are depleted during the thermal process, replacement electrodes can be joined to the column to maintain the length of the column extending into the furnace.
The melting of the metal may be brought about from an electrical arc between the scrap metal and the tip of the electrode column and the metal. As part of creating the arc, electrical current is built up in the electrode column and, in addition to the current being built up, heat is also built up in the electrode column as the current is accumulated. Additionally, heat may be given off from the molten bath of scrap metal. Still further, the arc itself generates large amounts of heat proximate to the electrode tip. With this build up of heat, the tip of the electrode column may be in the temperature range of over 3000° C.
In addition to the application of electricity, most furnaces include a chemical application to the bath such as but not limited to oxygen is a typical chemical component that is included in such application. With the tip of the column at the above described temperature and in the presence of oxidizing gases, this has a tendency to create an oxidizing environment in the furnace around the electrode column.